Such an electronic circuit is known, for instance, from Funkschau Os 83, Heft 4, 1963, page 216. The known electronic circuit is an oscillator with the frequency selective pan incorporating a series arrangement of a crystal and a variable inductance for the pulling of the crystal frequency.
Although the pulling aspect of the circuit is improved by inserting an inductance, there is another aspect, the dependence of the circuit fequency on the temperature, deteriorates considerably because the dependence of the circuit frequency the inductance introduces unfavourable influences. It is known, from DE-A 17 66 435, to compensate for the temperature behaviour of the crystal-oscillator by applying a d.c. current through an inductance in series with the crystal, which d.c. current is temperatue dependent. In this known oscillator a temperatue dependent current source is necessary in which the output is derived from the value of a temperature dependent resistor as a temperature sensor. Therefore, it is an object of the invention to provide an electronic circuit of the kind set forth wherein the inductance's influence on the temperature dependence of the frequency is considerably reduced, and without the use of a temperature sensor and/or other circuitry to generate a temperature-dependent electrical parameter to compensate for the temperature dependence of the crystal.